Three objects falling onto the runway from a plane as it took off on an international flight turned out to be two young men and a suitcase, leading to an emergency landing, a shutdown of the airport and a full inquiry.

Airport crews rushed to the site, fearing LAN Ecuador Airlines flight XL1438 departing Ecuador for New York had shed vital parts of the wheel assembly.

On arrival, however, personnel were horrified to find one person dead from falling about 300 metres onto the runway and another very severely injured, dying shortly afterwards.

Police chief of the Ecuadorian port city of Guayaquil, General Marcelo Tobar, told reporters the two were stowaways who had crawled into the landing gear section of the plane, a B737-300. Even more shockingly, the pair turned out to be younger than initially thought. The bodies were later identified as those of two teenage boys, cousins aged just 16 and 17, from a province outside Guayaquil.

The flight, headed for JFK Airport, the primary airport serving New York City, circled back upon learning of the incident, the Washington Post reported. It landed at airport of departure, Jose Joaquin de Olmedo International Airport. The departure terminal is pictured above.

Stowaways hiding in aircraft wheel wells (sometimes called undercarriage bays) and other external parts of aircraft nearly always die, though in 2014, a 15-year-old boy pulled off an almost impossible stunt and survived a flight from the US mainland to Hawaii, sitting in the wheel well of a Hawaiian Airlines B767.

As well as the tragic aspects, the latest case has security implications. If stowaways can reach an aircraft undetected, so can terrorists.